The Louisiana Coastal Restoration Plan proposes to build a small number of large river diversions. Another approach is to create small breaks in the levees to allow overflow into wetlands during floods that more closely resembles natural processes. This would be much less disruptive and would not come with the risk of large scale wetlands destruction which has followed all large scale diversions that have been built to this point.
Xu, Y. Jun. “Rethinking the Mississippi River diversion for effective capture of riverine sediments.” Sediment Dynamics from the Summit to the Sea; Xu, YJ, Allison, MA, Bentley, SJ, Collins, AL, Erskine, WD, Golosov, V., Horowitz, AJ, Stone, M., Eds (2014): 463-470.
There have been projects to test these small scale projects. It is not clear that any have built land in the long term.